Methods and apparatus for reducing undeliverable server-initiated IP traffic in a wireless network

ABSTRACT

A host server is operative to control the pushing of user data messages to a plurality of mobile communication devices adapted to communicate in a wireless communication network. In particular, the host server is adapted to cause, for each one of the mobile communication devices operating in the wireless communication network, user data messages to be pushed to a mobile communication device via a packet data connection; receive, from a serving node in the wireless communication network, an IP notification message having an IP destination address of the host server and including an identification or address that identifies one of the mobile communication devices, the IP notification message being produced in response to a termination of packet data connectivity for the identified mobile communication device; and in response to receiving the IP notification message, at least temporarily refrain from pushing user data messages to the identified mobile communication device. The IP notification message may be formatted and communicated based on an existing protocol, such as Internet Control Message Protocol (ICMP), or any other suitable protocol.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.non-provisional patent application entitled “Methods And Apparatus ForReducing Undeliverable Server-Initiated IP Traffic In A WirelessNetwork” having application Ser. No. 10/839,388 and filing date of 5 May2004, now U.S. Pat. No. 7,366,093, which claims further priority to U.S.Provisional Patent Application entitled “Control Information” havingapplication No. 60/468,451 and filing date of 7 May 2003, whichapplication being hereby incorporated by reference herein.

BACKGROUND

1. Field of the Technology

The present application relates generally to wireless communicationnetworks, and more particularly to methods and apparatus for reducingundeliverable server-initiated IP traffic to mobile stations in awireless communication network.

2. Description of the Related Art

Internet Protocol (IP) communication networks were originallyimplemented in land-line environments. Over the past decade, however,emerging wireless networks have been designed with at least some form ofIP protocol support. Wireless networks operating in accordance withGeneral Packet Radio Service (GPRS), for example, have been specified tooffer a form of native IP networking. In general, GPRS utilizes a seriesof data-centric network protocols which operate in conjunction withtraditional Global Systems for Mobile Communication (GSM) networks.

Networks like those based on GSM/GPRS utilize proprietary tunnelingtechniques for creating IP-based addressing mechanisms that work overthe top of traditional network infrastructure protocols that are notIP-based. In the case of GSM/GPRS, an IP tunnel is utilized which isreferred to as a Packet Data Protocol (PDP) Context. A PDP Contextutilizes a tunneling service on behalf of two entities, communicatingonly using native IP packets. The creation of a PDP Context causes an IPaddress to be allocated and assigned to a mobile station which is linkedto an Access Point Name (APN) or host system. Such proprietary methodsof exchanging IP packets create design problems and challenges when thestate or status of one of the entities changes.

Since modern wireless networks utilize an IP protocol for data exchange,at least some capabilities associated with sending asynchronous host orserver-initiated messages (i.e. “pushing” data) to mobile stations havebeen limited and compromised. In a wireless environment, there are manyreasons why an attempt to communicate with a mobile station might fail.At any given time, a host attempting to initiate a message to a mobilestation has very little knowledge of whether the mobile station isin-coverage or out-of-coverage, whether it has been switched off,whether it is still assigned to the same IP address, or whether an IPdata packet has been ever delivered. These problems are exacerbated bythe fact that wireless networks treat each mobile station as a “client”,which is not well-suited for the returning of status information inhost-initiated environments.

Communication failures are generally only communicated betweenproprietary nodes within the network infrastructure. A protocol referredto as the Internet Control Message Protocol (ICMP) defined by RequestFor Comments (RFC) 792 by the Internet Engineering Task Force (IETF),for example, provides for the reporting of IP messages that cannot bedelivered. In particular, ICMP provides limited feedback to both hostsand mobile stations whenever an actual IP message failure occurs.However, conventional ICMP does not inform a host when the mobilestation's state or status changes spontaneously. Such state changes arevery common in a wireless environment. For example, a network operatormay set timeout values for idle PDP Contexts which may be closed wheninactivity timers have expired. Note also that without feedbackregarding the termination of a PDP Context, the host often utilizes anincorrect IP address when it attempts to send information to a mobilestation. When utilizing dynamic IP address assignment, apreviously-assigned IP address may be already reassigned which mayresult in the wrong mobile station receiving the information from thehost.

Accordingly, there is a resulting need for methods and apparatus thatovercome the deficiencies of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of present invention will now be described by way of examplewith reference to attached figures, wherein:

FIG. 1 is a block diagram showing an exemplary wireless system whichincludes a wireless network having a core wireless networkinfrastructure;

FIG. 2 is an expanded block diagram of the wireless system of FIG. 2;

FIG. 3 is an expanded block diagram of the wireless system of FIG. 2including a notification function entity;

FIG. 4 is an exemplary exchange diagram of data exchanges that takeplace when a Packet Data Protocol (PDP) Context for a mobile station hasbeen lost as identified by a Serving GPRS Support Node (SGSN);

FIG. 5 is an exemplary exchange diagram of data exchanges that takeplace when a PDP Context for a mobile station has been lost asidentified by a Gateway GPRS Support Node (GGSN); and

FIG. 6 is a flowchart for summarily describing the general method ofreducing undeliverable server-initiated IP traffic to mobile stationswithin the wireless network.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one illustrative example of the techniques described herein, a methodof reducing undeliverable server-initiated IP traffic within a wirelesscommunication network includes the steps of identifying that a dataconnection for communicating server-initiated IP messages from a hostserver to a mobile station has been lost or terminated; causing anotification message having a destination address corresponding to thehost server to be produced based on identifying that the data connectionhas been lost or terminated; and causing the notification message to besent to the host server. The notification message may cause the hostserver to at least temporarily refrain from communicating and/or toqueue server-initiated IP messages intended for the mobile station. Thenotification message may be formatted and communicated based on anexisting protocol, such as Internet Control Message Protocol (ICMP), orany other suitable protocol. Advantageously, undeliverableserver-initiated IP traffic to mobile stations is reduced within thewireless network.

Referring to FIG. 1, a block diagram of an exemplary wireless system 21which includes a wireless communication network 20 having a corewireless network infrastructure 18 and one or more base stations 16 isshown. Base stations 16 communicate with mobile stations 10, 12 over awireless link 14 utilizing radio frequency (RF) protocols. Examples ofsuch RF protocols include Code Division Multiple Access (CDMA), TimeDivision Multiple Access (TDMA), and Frequency Division Multiple Access(FDMA) radio protocols used in virtually all wireless networks. Corewireless network infrastructure 18 is responsible for all other networkfunctions including authentication, routing, provisioning, and IPaddress management.

One or more data sources 26 are the initiators of data to be “pushed” tomobile stations 10, 12. In FIG. 1, there are two data sources shown butseveral additional data sources may be utilized. Server-initiated IPmessages are sent from data source 26 to mobile stations 10, 12 after aninitial setup for mobile stations 10, 12. Data source 26 may be aspecific application server for mobile stations 10, 12 which may bereferred to as a host system or server. Data that are “pushed”asynchronously from data source 26 to mobile stations 10, 12 may includeelectronic mail (e-mail) message data, stock data, specialized calldispatch data, customer data, weather data, sports data, calendar orschedule data, and a wide-range of other data types. Such data areregularly sent and received substantially in “real-time” by mobilestations 10, 12. Mobile stations 10, 12 may visually display andotherwise utilize the data as appropriate.

A gateway function 22, which may include one or more gateway servers orprocessors, is provided for interconnection functions between mobilestations 10, 12 and non-wireless network components (e.g. data source26). The interconnection features of gateway function 22 include therouting traffic from a private IP domain within wireless network 20 tothe public domain of the Internet, authorizing mobile stations 10, 12 touse particular gateway functions, and providing an asynchronous “push”mechanism for data previously requested by mobile stations 10, 12. In anexemplary embodiment, data source 26 and gateway function 22 areconnected through an Internet connection 24 in FIG. 1.

A “host server” referred to herein may be an application server (e.g.data source 26) that initiates push communications to mobile stations,or an intermediate server such as gateway function 22 which manages oneor more push application servers (e.g. data source 26) for providingsubscriber services for mobile stations 10, 12. In this context, gatewayfunction 22 may include a Wireless Access Protocol (WAP) server, apush-proxy server, or what is referred to in the industry as a pushfunction for mobile stations 10, 12.

In FIG. 2, there is shown an expanded version of wireless system 21 ofFIG. 1 which operates based on Global Systems for Mobile Communications(GSM) and General Packet Radio Service (GPRS) standards. Core wirelessnetwork infrastructure 18 in FIG. 2 reveals routing and operationalnodes, specifically, Serving GPRS Support Nodes (SGSNs) 30, 34 andGateway GPRS Support Nodes (GGSNs) 32, 36. SGSNs 30, 34 and GGSNs 32, 36may include conventional components such as computer processors and/orservers. GGSNs 32, 36 are wireless network gateways and thereforeinclude wireless network gateway processing and/or servers.

As understood by those skilled in the art, this is not an exhaustivedepiction of all components within a GSM/GPRS, Universal MobileTelephone Service (UMTS), or Enhanced Data Rates For GSM Evolution(EDGE) type network, but rather just the primary components involved inrouting and managing information for mobile stations 10, 12 pertinent tothis discussion. Although the present embodiment relates to GSM/GPRS, itis clear to one skilled in the art that network components for CDMA,iDEN, UMTS, EDGE, etc. may be utilized as alternatives. Specifically,for example, a Packet Data Serving Node (PDSN) of a CDMA network (e.g.cdma2000) may be utilized to produce and cause the notification messagesto be sent to the host server. Note also that the version of IP protocolutilized (i.e. IPv4 or IPv6) has no effect on the techniques of thepresent application.

Core wireless network infrastructure 18 of FIG. 2 also includes AccessPoint Names (APNs) 40, 42 to identify which appropriate gateway function22, 28 should be utilized. This is necessary in order to allow mobilestations 10, 12 to select different gateway functions 22, 28, and thusdifferent IP networks 24, 44 and different data sources 26, 46. Ingeneral, APNs 40, 42 act as end-point identifiers, routing address andprovisioning points for mobile stations 10, 12 to communicate withentities outside of wireless network 20. APNs 40, 42 are qualifiedsimilar to Internet domain names (i.e. by label.label.label string).They are used in the network to determine which GGSN 32, 36 andtherefore which IP network 24, 44 mobile stations 10, 12 need to access.However, APNs 40, 42 have no IP address and act as simple routers whichtake the information provided by either mobile stations 10, 12 orgateway functions 22, 28 and route it appropriately through wirelessnetwork 20.

As part of a provisioning process, each mobile station 10, 12 isassociated with one or more APNs 40, 42 in a mapping table. SGSNs 30, 34manage such mapping table information within core wireless networkinfrastructure 18 and subsequently use it to select which GGSN 32, 36 toroute information to for a given mobile station 10, 12. The mappingtable stores a permanent identifier (e.g. a subscriber ID) for eachmobile station 10, 12, a current dynamically-assigned IP addressassociated therewith, and one or more APN addresses associatedtherewith.

During normal operation, GGSNs 32, 36 receive one or moreserver-initiated IP messages from gateway functions 22, 28 from datasources 26, 46. Intended for mobile stations 10, 12, these messages areforwarded via core wireless network infrastructure 18 to mobile stations10, 12 over wireless link 14 through base station 16. Note, however,that an error may occur when trying to send such a message to mobilestation 10, 12. In these situations, conventional Internet ControlMessage Protocol (ICMP) is used to report a specific failure to send themessage. This is insufficient, however, and direct feedback regardingdata connection status of mobile stations 10, 12 is needed.

Using techniques of the present application, the data connection statusof mobile stations 10, 12 is provided. Broadly, a data connection forcommunicating server-initiated IP messages from a host server to amobile station is identified to be lost or terminated. The host servermay be an application server (e.g. data source 26 or 46) that initiatespush communications to mobile stations, or an intermediate server suchas gateway function 22 (WAP Server, Push-Proxy Server, or Push Function)which manages one or more push application servers (e.g. data source 26)for providing subscriber services for mobile stations 10, 12. The dataconnection may be identified to be lost or terminated by GGSNs 32, 36,for example. In response to such identification, a notification messagehaving a destination address corresponding to the host server isproduced and sent immediately to the host server. The notificationmessage is indicative of the lost or terminated data connection. Thenotification message may cause the host server to at least temporarilyrefrain from communicating and/or to queue pending or futureserver-initiated IP messages intended for the mobile station. This way,undeliverable server-initiated IP traffic to mobile stations is reducedwithin the wireless network.

In FIG. 3, there is shown a further expanded version of wireless system21 of FIG. 2 which reveals a notification function 60. Notificationfunction 60 may be included as part of gateway function 28, where in thedrawing it has been extracted for greater illustrative clarity.Alternatively, notification function 60 may involve a component separatefrom gateway function 28 such as a separate notification processor orserver. Notification function 60 serves the purpose of managingnotifications when data connections for mobile stations 10, 12 becomelost or terminated. Thus, in response to a lost or terminated dataconnection, a notification message is sent to a notification IP addresswhich is managed by notification function 60. In response, notificationfunction 60 updates any components that need to know the information(e.g. one or more host servers for mobile station 10) or simply updatesa database for mobile station 10.

An APN provisioning mechanism is used to establish a relationshipbetween APNs 40, 42 and gateway functions 22, 28. This relationshipestablishes a physical communication path between GGSNs 32, 36 andgateway functions 22, 28 for subsequent communication. To facilitate anotification mechanism, a notification IP address is established withinthe APN provisioning mechanism. This notification IP address acts as aconfigured IP path for notification messages that are sent to a givenAPN.

In the present embodiment, GGSNs 32, 36 are capable of producingnotification messages which are indicative of lost or terminated dataconnections of mobile stations 10, 12. Such notification messages areproduced and sent immediately in response to the identification of thelost or terminated data connections. Alternatively, the sending ofnotification messages may be delayed for a small time period beforedelivery. In any case, the notification IP address is used as adestination address to an entity (e.g. a host server) that is preparedto act upon it, directly or indirectly. In response to a givennotification message, notification function 60 may at least update alocal database, send a message to defined gateway functions 22, 28,and/or perform other various activities to ensure better delivery ofinformation to mobile stations 10, 12. It is noted that, in somewireless networks, the need to define the notification IP address may beunnecessary as gateway functions 22, 28 may be reachable directly from acore wireless network node.

Note that a notification message produced for a single terminated dataconnection may be sent to more than one host server. In this case, thenotification message may be viewed as being “broadcasted” to a pluralityof host servers associated with a plurality of IP addresses. Forexample, GGSN 32 may directly broadcast the notification message to aplurality of host servers associated with a plurality of IP addresses.As another example, GGSN 32 may send a single notification message togateway function 22, which in turn broadcasts the notification messageto a plurality of host servers (e.g. data sources 26, 46). As evenanother example, GGSN 32 may send a single notification message tonotification function 60, which in turn broadcasts the notificationmessage to a plurality of gateway functions 22, 28, which in turn maybroadcast the notification message to a plurality of additional hostservers (e.g. data sources 26, 46). A list of IP addresses is keptstored in a suitable location which depends on the embodiment utilized.

FIG. 4 is a message flow diagram where a data connection forserver-initiated messages to mobile station 10 is identified to be lostor terminated. During normal operation, gateway function 22 causes aserver-initiated message 100 to be sent to GGSN 32. GGSN 32 routesmessage 100 to SGSN 30 as a message 102. At this stage, GGSN 32 may havemodified the addressing information and perform basic checks on message100. Each of the networks described earlier will have a similar functionto determine that message 100 is valid and correctly formatted. SGSN 30then identifies the correct base station and routes a message 104 tomobile station 10. This may be performed using a dynamically-assigned IPaddress that is currently associated with mobile station 10. Thisprocess repeats as shown by further message communications 106, 108, and110.

At some point in time, however, a data connection for sendingserver-initiated messages to mobile station 10 may become lost orterminated. The data connection may be a Packet Data Protocol (PDP)Context for mobile station 10. Alternatively, the data connection mayinvolve a wireless link between mobile station 10 and the base station.Thus, the data connection may be deemed lost when the PDP Context isterminated, for example, or when mobile station 10 is out-of-coveragewith the base station.

Termination of the PDP Context may be initiated by SGSN 30, for example,after a predetermined time period of communication inactivity expiresfor the PDP Context associated with mobile station 10. In some cases, adynamically-assigned IP address that was previously associated with thePDP Context is reassigned and given to another mobile station 12. Inresponse to the PDP Context termination, SGSN 30 normally sends amessage 122 to GGSN 32 indicating that the PDP Context for mobilestation 10 has been deleted 120. The communication of this message 122may take place, for example, over the GPRS Tunnelling Protocol Controlplane (GTP-C) defined in 3GPP specification 29.060. The procedurefollowed by SGSN 30 is referred to as a “GPRS Detach” procedure or a“GPRS PDP Context Deactivation” procedure. Message 122 may carry asubscriber ID of mobile station 10 and other information, such as the IPaddress currently associated with mobile station 10. Providing thesubscriber ID in the message allows GGSN 32 to update any mapping tables(such as the mapping table which associates mobile station 10 to an APN)to thereby reflect the current connection state of mobile station 10.Message 122 may appear as an SGSN message directed to GGSN 32 with acause values of IP address release 122. For reference, note that the3GPP 29.060 specification has a full list of cause values.

In response to message 122, GGSN 32 produces a notification message 124indicative of the lost/terminated data connection for mobile station 10.GGSN 32 immediately causes notification message 124 to be sent to thehost server. The notification message may cause the host server to atleast temporarily refrain from communicating and/or to queue pending orfuture server-initiated IP messages intended for mobile station 10. Amobile station identifier for mobile station 10, such as its subscriberID or IP address, which is stored at the host server may be deleted sothat future messages do not get sent to mobile station 10 using thatidentifier.

The notification message is IP-based and utilizes the IP address of thehost server as the destination address. Specifically, the destinationaddress of the notification message may be derived from the configurednotification IP address for APN 40 (FIGS. 2-3). The notification IPaddress may be managed either by notification function 60 or,alternately, by gateway function 22. It is noted that, in some networks,this additional IP address might not be needed if the network alreadyhas the correct IP address for gateway function 22.

In one embodiment, the format and communication of the notificationmessage is specifically based on an Internet Control Message Protocol(ICMP). As a specific example, the notification message is anasynchronous ICMP message having a type value of 3 (“destinationunreachable”) and a code value of 1 (“host unreachable”) to indicatethat the PDP Context has been lost/terminated for mobile station 10.Note that other ICMP type and code values can be used other then thatdescribed herein. ICMP could be extended to include wireless-specificmessage types and is not limited to currently-defined ICMP types. In analternative embodiment, the format and communication of the notificationmessage is not ICMP-based and may utilize any suitable protocol.Preferably, the subscriber ID of the mobile station is included in thenotification message. This allows the recipient (e.g. host server) toappropriately update the data connection status of the correct mobilestation 10, 12.

FIG. 5 is another message flow diagram where, again, a data connectionfor server-initiated messages to mobile station 10 is identified to belost or terminated. Here, GGSN 32 initiates termination of the PDPContext, especially in the situation where the host system establishedthe PDP Context and subsequently wishes to terminate it. The basic stepsare the same as FIG. 4, except that GGSN 32 initiates the PDP Contextdeactivation using the GTP-C protocol with SGSN 30. This procedure iscalled the “PDP Context Deactivation Initiated by GGSN” procedure. Afterdeletion 130 of the PDP Context for mobile station 10, GGSN 32 causes aGTP message 132 to be sent to SGSN 30. Thereafter, GGSN 32 causes anotification message 134 to be sent to the host server identified by thenotification IP address.

Note that there are a wide variety of additional or alternative errorconditions in the networks where a notification message may be producedand delivered in accordance with the present techniques. Some of theseadditional conditions may include situations where the mobile station isGPRS-detached; the mobile station has initiated the shutdown of the PDPContext (similar to examples shown in FIG. 4 and FIG. 5); the mobilestation is not GPRS-responding, the mobile station is turned off,battery has died, or has been out-of-coverage for an extended period oftime; the mobile station refuses; the mobile station is having internalproblems (e.g. perhaps it has run out of resources but it is refusing toaccept messages through the PDP Context); little or no resources areavailable; the network is having spontaneous resource issues (allowshosts to temporarily refrain from utilizing resources until they areavailable); a system failure; the network is experience a system failurewhich could effect data transfer (allows hosts that are trying to sendto back-off until systems are repaired); the GPRS connection issuspended or temporarily suspended; data traffic is affected; and thePDP Context not found, lost, or no longer available.

FIG. 6 is a flowchart which summarily describes a general method ofreducing undeliverable server-initiated IP traffic within the wirelesscommunication network. This method may be implemented as computersoftware instructions which are stored on a storage medium (e.g. memory,computer disk, CD-ROM, etc.) and executed at least in part by a gatewayprocessor or server (e.g. in a GGSN) in a wireless communicationnetwork. Before the method of FIG. 6, a mobile station is operating in awireless communication network and is receiving server-initiated IPmessages from a host server over a data connection. The server-initiatedIP data may include, as examples, e-mail messages, real-time stockquotes, real-time weather information, etc., which are visuallydisplayed and otherwise usable at the mobile station.

Beginning at a start block of FIG. 6, the data connection forcommunicating the server-initiated IP messages from the host server tothe mobile station is identified to be lost or terminated (step 602).The data connection may be a Packet Data Protocol (PDP) Context or awireless data link, for example. In response to identifying that thedata connection has been lost or terminated, a notification messagehaving a destination address corresponding to the host server isproduced (step 604). The host server may be the application server thatinitiates such push communications to the mobile station, or anintermediate server such as a gateway server (WAP, push-proxy, or pushfunction) which manages one or more application servers on behalf of themobile station for subscriber services.

The notification message is an IP message which is routable in thewireless network. In particular, the notification message may beformatted and communicated based on an Internet Control Message Protocol(ICMP) or other suitable protocol. If the data connection that was lostor terminated is a PDP Context, the notification message may be referredto as a PDP Context State Notification. In any case, the notificationmessage is immediately sent to the host server (step 606). Upon itsreceipt, the notification message may cause the host server to at leasttemporarily refrain from communicating and/or to queue server-initiatedIP messages intended for the mobile station. A mobile stationidentifier, such as its subscriber ID or IP address, which is stored atthe host server may be deleted so that future messages do not get sentto the mobile station using that identifier. Other suitable responses bythe host server may be performed in addition to or in lieu of theabove-mentioned responses.

Final Comments. Methods and apparatus for reducing undeliverableserver-initiated IP traffic in a wireless communication network havebeen described. One illustrative method includes the steps ofidentifying that a data connection for communicating server-initiated IPmessages from a host server to a mobile station has been lost; causing anotification message having a destination address corresponding to thehost server to be produced based on identifying that the connection islost; and causing the notification message to be sent to the hostserver. The notification message may cause the host server to at leasttemporarily refrain from communicating and/or to queue server-initiatedIP messages intended for the mobile station. The notification messagemay be based on an Internet Control Message Protocol (ICMP) or othersuitable protocol.

A wireless network gateway of the present application includes a gatewayprocessor; a storage medium; and computer instructions stored in thestorage medium. The computer instructions may be executable by thewireless network gateway processor for reducing undeliverableserver-initiated IP traffic within a wireless communication network byidentifying that a data connection for communicating server-initiated IPmessages from a host server to a mobile station in a wirelesscommunication network has been lost; causing a notification messagehaving a destination address corresponding to the host server to beproduced based on identifying that the data connection has been lost;and causing the notification message to be sent to the host server.

A wireless communication system of the present application includes oneor more base stations; a Serving GPRS Support Node (SGSN) coupled in thewireless communication network for communications with the one or morebase stations; and a Gateway GPRS Support Node (GGSN) coupled in thewireless communication network for communications with the SGSN. TheGGSN includes a GGSN processor; a storage medium; and computerinstructions stored in the storage medium. The computer instructions areexecutable by the GGSN processor for reducing undeliverableserver-initiated IP traffic within the wireless communication systemfrom a host server by identifying that a data connection forcommunicating server-initiated IP messages from the GGSN server to amobile station has been lost; causing a notification message having adestination address corresponding to the host server to be producedbased on identifying that the data connection has been lost; and causingthe notification message to be sent to the host server.

The above-described embodiments of invention are intended to be examplesonly. Note that the mobile station may be associated with a permanent IPaddress as opposed to a dynamically-assigned IP address from thenetwork. In addition, although the detailed embodiment relates toGSM/GPRS, it is clear to one skilled in the art that network componentsfor CDMA, iDEN, UMTS, EDGE, etc. may be utilized as alternatives.Specifically, for example, a Packet Data Serving Node (PDSN) of a CDMAnetwork may be utilized to produce and cause the notification messagesto be sent to the host server. Alterations, modifications, andvariations may be effected to particular embodiments by those of skillin art without departing from scope of invention, which is definedsolely by claims appended hereto.

1. A method in a host server adapted for connection outside of awireless communication network for controlling the pushing of datamessages to a plurality of mobile communication devices adapted tocommunicate in the wireless communication network, the method comprisingthe acts of: for each one of the mobile communication devices operatingin the wireless communication network: causing, by the host server, datamessages to be pushed to the mobile communication device via a packetdata connection; receiving, in the host server, an IP notificationmessage originating from a serving node in the wireless communicationnetwork, the IP notification message having an IP destination address ofthe host server and including an identification or address thatidentifies one of the mobile communication devices, the IP notificationmessage being produced in response to a termination of the packet dataconnection for the identified mobile communication device and indicatingthat the identified mobile communication device is unavailable toreceive data messages; and in response to receiving the IP notificationmessage: at least temporarily refraining, in the host server, frompushing data messages to the identified mobile communication device. 2.The method of claim 1, wherein the IP notification message is formattedin accordance with Internet Control Message Protocol (ICMP).
 3. Themethod of claim 1, wherein the IP destination address is configured inan Access Point Name (APN) provisioning mechanism for an APN connectedbetween the wireless communication network and the host server.
 4. Themethod of claim 1, wherein the packet data connection comprises a PacketData Protocol (PDP) context.
 5. The method of claim 1, wherein thetermination of the packet data connection comprises a packet servicedetachment for the identified mobile communication device.
 6. The methodof claim 1, wherein the wireless communication network operates inaccordance with General Packet Radio Service (GPRS), and the servingnode comprises a Gateway GPRS Support Node (GGSN).
 7. The method ofclaim 1, comprising the further acts of: in response to receiving the IPnotification message: at least temporarily queuing subsequent datamessages for the identified mobile communication device.
 8. The methodof claim 1, which is embodied in a storage medium and a computersoftware instructions stored in the storage medium, where the computersoftware instructions are executable by one or more processors of thehost server for performing the method.
 9. A host server which isoperative to control the pushing of data messages to a plurality ofmobile communication devices adapted to communicate in a wirelesscommunication network, the host server being adapted to cause, for eachone of the mobile communication devices data messages to be pushed tothe mobile communication device via a packet data connection; receive anIP notification message originating from a serving node in the wirelesscommunication network, the IP notification, message having an IPdestination address of the host server and including an identificationor address that identifies one of the mobile communication devices, theIP notification message being produced in response to a termination ofthe packet data connection for the identified mobile communicationdevice and indicating that the identified mobile communication device isunavailable to receive data messages; and in response to receiving theIP notification message, at least temporarily refrain from pushing datamessages to the identified mobile communication device.
 10. The hostserver of claim 9, wherein the IP notification message is formatted inaccordance with Internet Control Message Protocol (ICMP).
 11. The hostserver of claim 9, wherein the IP destination address is configured inan Access Point Name (APN) provisioning mechanism for an APN connectedbetween the wireless communication network and the host server.
 12. Thehost server of claim 9, wherein the packet data connection comprises aPacket Data Protocol (PDP) context.
 13. A method in a gateway forcontrolling the pushing of data messages between a push applicationserver situated outside of a wireless communication network and aplurality of mobile communication devices adapted to communicate in thewireless communication network, wherein for each one of the mobilecommunication devices data messages are pushed between the pushapplication server and the mobile communication device via a packet dataconnection, the method comprising the acts of: receiving, in thegateway, an IP notification message originating from a serving node inthe wireless communication network, the IP notification message havingan IP destination address of the gateway and including an identificationor address that identifies one of the mobile communication devices, theIP notification message being produced in response to a termination ofthe packet data connection for the identified mobile communicationdevice and indicating that the identified mobile communication device isunavailable to receive data messages; and in response to receiving theIP notification message: cause the push application server to at leasttemporarily refrain from pushing user data messages to the identifiedmobile communication device.
 14. The method of claim 13, wherein the IPdestination address is configured in an Access Point Name (APN)provisioning mechanism for an APN connected between the wirelesscommunication network and the gateway.
 15. The method of claim 13,wherein the IP notification message is formatted in accordance withInternet Control Message Protocol (ICMP).
 16. The method of claim 13,wherein the packet data connection comprises a Packet Data Protocol(PDP) context.
 17. The method of claim 13, wherein the termination ofpacket data connectivity comprises a packet service detachment for theidentified mobile communication device.
 18. The method of claim 13,wherein the wireless communication network operates in accordance withGeneral Packet Radio Service (GPRS), and the serving node comprises aGateway GPRS Support Node (GGSN).
 19. A gateway operative to control thepushing of data messages from a push application server situated outsideof a wireless communication network and a plurality of mobilecommunication devices adapted to operate in the wireless communicationnetwork, wherein for each one of the mobile communication devices, datamessages are pushed to the mobile communication device via a packet dataconnection; receive an IP notification message originating from aserving node in the wireless communication network, the IP notificationmessage having an IP destination address of the gateway and including anidentification or address that identifies one of the mobilecommunication devices, the IP notification message being produced inresponse to a termination of the packet data connection for theidentified mobile communication device and indicating that theidentified mobile communication device is unavailable to receive datamessages; and in response to receiving the IP notification message,causing the push application server to at least temporarily refrain frompushing data messages to the identified mobile communication device. 20.The gateway of claim 19, wherein the IP destination address isconfigured in an Access Point Name (APN) provisioning mechanism for anAPN connected between the wireless communication network and thegateway.
 21. The gateway of claim 19, wherein the IP notificationmessage is formatted in accordance with Internet Control MessageProtocol (ICMP).
 22. The gateway of claim 19, wherein the packet dataconnection comprises a Packet Data Protocol (PDP) context.
 23. Thegateway of claim 19, wherein the wireless communication network operatesin accordance with General Packet Radio Service (GPRS), and the servingnode comprises a Gateway GPRS Support Node (GGSN).
 24. The host serverof claim 9, wherein the computer instructions are further executable toat least temporarily queue subsequent data messages for the identifiedmobile communication device in response to receiving the IP notificationmessage.